1. Field of Invention
This invention relates to a method for checking the correct coupling of an adding device to a therapeutic appliance, which includes an extracorporeal circuit with which the adding device is connected such that during operation of the therapeutic appliance a drug can be introduced into the extracorporeal circuit by means of the adding device, which preferably is coupled on the arterial side of an extracorporeal blood circuit upstream or downstream of the blood pump.
2. Description of the Prior Art
From DE 38 37 298 C1, there is known an extracorporeal blood circuit with a heparin syringe infusing into the region of negative pressure on the suction side of the blood pump disposed in the arterial conduit, wherein an arterial clamp or an arterial valve is provided on the arterial blood conduit upstream of the infusion point and a pressure measurement point is provided before the blood pump in downstream direction. Here, it is described in detail how a metered amount of heparin can be supplied during blood treatment.
From U.S. Pat. No. 6,558,347 B1, there is known a peristaltic infusion pump for infusing a drug into a patient. There is described an apparatus and a method for checking the correct operation of a finger pump or the correct positioning of the tube in the finger pump. By closing a valve on the pressure side of the pump, a closed tube volume is produced, which is put under excess pressure by specifically starting the pump against the closed valve. The pressure in the corresponding tube portion is measured.
In an adding device coupled to a therapeutic appliance, it is of decisive importance that coupling is effected correctly. In particular when coupling on the suction side of a pump disposed in the extracorporeal circuit, a number of risks and errors can occur. The following possible errors can occur:                The adding device does not operate properly, whereby the drug to be added is sucked in incorrectly (problem of the unintended bolus);        when a conduit is not connected tightly, microbubbles will occur during suction;        when using foreign models of the adding device, e.g. heparin syringes of foreign manufacturers, a necessary compensation of play is not created, so that the adding device does not operate properly.        